Portion of a shoe midsole



FIG. 1 is a perspective view of a portion of a shoe midsole showing my new design;

FIG. 2 is another perspective view thereof; and,

FIG. 3 is a side view thereof.

The uneven broken line showing of the remainder of the shoe is for illustrative purposes only and forms no part of the claimed design.

The broken lines immediately adjacent to the shoe upper, and the base of the midsole in the figures, define the boundary of the claimed design. The broken boundary lines, form no part of the claim. 

The ornamental design for a portion of a shoe midsole, as shown and described. 